JP2509807Y2 - Control structure of passenger airbag system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] <Industrial field of application> The present invention relates to a control structure for a vehicle airbag device, and more particularly to a controller for a passenger airbag for a passenger.

<Prior Art> An airbag device for protecting an occupant from a sudden deceleration while a vehicle is traveling has been known. In addition, it is actually desirable to use the airbag device not only in the driver's seat but also in the passenger seat.

However, unlike the driver's seat, the passenger's seat does not always have an occupant. For example, if the airbag device on the passenger's side is activated against sudden deceleration of the vehicle even when there is no passenger, the airbag is Since it cannot be reused, the usage cost rises. Therefore, it is conceivable to provide a sensor for detecting the presence of a passenger in the passenger seat so as not to activate the airbag device when there is no passenger, but in order to ensure the operational reliability of this passenger sensor. There was a problem that enormous cost was required.

<Problems to be Solved by the Invention> In view of the problems of the prior art as described above, the main purpose of the present invention is to secure the operation reliability of the airbag device and reduce the use cost thereof for the passenger seat air. It is to provide a control device for the bag.

[Construction of the Invention] <Means for Solving the Problems> According to the present invention, such a purpose is to inflate a bag-like airbag from the front toward the passenger in the passenger seat during a rapid deceleration of the vehicle. And a passenger airbag control device for protecting the passenger from a front obstacle, based on a signal from the passenger sensor for detecting the presence or absence of a passenger in the passenger seat, and a signal from the passenger sensor. A control circuit that activates the airbag device only when a passenger is present in the passenger seat, and a fail-safe circuit that activates the airbag device when an abnormality of the occupant sensor is detected. This is achieved by providing a control device for a passenger airbag, which is characterized by the above.

<Operation> In this way, the airbag device can be activated only when there is a passenger in the passenger seat or the presence / absence of the passenger is unknown, and the operational reliability of the airbag device is not impaired.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic circuit diagram showing the configuration of a vehicle airbag device to which the present invention is applied.

A steering wheel provided in a front position of a driver's seat in a vehicle compartment is folded and buried with a bag-shaped airbag that can be instantly inflated toward the driver with propellant or the like. A main sensor 1 and a safing sensor 2 that detect a condition for inflating the airbag, that is, a rapid deceleration of the vehicle due to a collision, are provided at appropriate places on the vehicle. The main sensor 1 and the safing sensor 2 are connected to the power source 3
Is connected to the ignition device 4 for igniting the propellant for inflating the driver's airbag via a valve to form a closed circuit.

On the other hand, in the front position of the passenger seat in the passenger compartment, a bag-shaped airbag which can be instantly inflated toward the passenger in the passenger seat with a propellant or the like is also folded and buried. An ignition device 5 for igniting the propellant for inflating the airbag is connected in parallel with the ignition device 4 via a collector and an emitter of a transistor 7, and the ignition is also performed through a collector and an emitter of a transistor 8. It is connected in parallel with the device 4.

An occupant sensor 10 for detecting the presence or absence of an occupant is provided in the passenger seat. The occupant sensor 10 is connected to the base of a switching transistor 7 as a control circuit via an occupant detection circuit 6. In the passenger detection circuit 6,
A fail-safe circuit 11 is provided for monitoring the operating state and applying a voltage to the base of the transistor 8 and activating a warning device 12 for an occupant when an abnormality occurs in the occupant detection circuit 6.

As well shown in FIG. 2, the switch 10a in the occupant sensor 10 is connected to a constant voltage source and the occupant detection circuit 6 is connected.
It is connected to one input terminal of the internal comparator 14. The other input terminal of the comparator 14 is also connected to the constant voltage source. When the switch 10a is turned on (there is a passenger), the seating detection signal (H) is output from the output terminal of the comparator 14 and the voltage is applied to the base of the transistor 7. Is applied.

Further, one input terminal of the comparator 15 in the fail-safe circuit 11 is connected to the constant voltage source via the bypass line A in the passenger sensor 10, and the other input terminal of the comparator 15 is also connected to the constant voltage source. Passenger sensor
If there is a disconnection between 10 and the passenger detection circuit 6 or if the connection is abnormal and the resistance value changes, an abnormality detection signal (H) is output from the output terminal of the comparator 15 and is output to the base of the transistor 8. A voltage is applied.

 Next, the operation of this embodiment will be described.

First, when there is no abnormality in the passenger sensor 10 and there is a passenger in the passenger seat, as shown in FIG.
The switch 10a of the passenger sensor 10 is turned on, the seating detection signal (H) is output from the output terminal of the comparator 14,
Since a voltage is applied to the base of the transistor 7,
Power can be supplied to the ignition device 5 in FIG. 1, and the passenger airbag can be operated.

When there is no passenger in the passenger seat, the switch 10a of the passenger sensor 10 is turned off, and the seating detection signal is not output from the output terminal of the comparator 14. Then, power cannot be supplied to the ignition device 5 in FIG. 1, and the passenger airbag cannot operate.

The voltage applied to one input terminal of the comparator 15 becomes lower than a predetermined value, such as when the passenger sensor 10 and the passenger detection circuit 6 are disconnected or when the resistance changes due to an abnormal connection. In this case, the abnormality detection signal (H) is output from the output terminal of the comparator 15 and the voltage is applied to the base of the transistor 8, so that power can be supplied to the ignition device 5 in FIG. The airbag becomes operable. Then, when the main sensor 1 and the safing sensor 2 are actually turned on, power is supplied to the ignition device 4 and the ignition device 5, the propellant of each airbag is ignited, and each airbag swells.

Needless to say, the present invention is not limited to the above-described embodiment and can be applied in various ways. For example, in the present embodiment, the fail-safe circuit detects disconnection of the occupant sensor.
A test circuit may be provided for actually confirming the on / off operation of the occupant sensor when the vehicle starts traveling.

Further, in the present embodiment, only the transistor 7 functioning as a switch is shown as the control circuit, but it goes without saying that elements such as resistors associated with the transistor may actually be included in the control circuit in some cases. .

[Effect of the Invention] As described above, according to the present invention, the airbag device is activated only when the passenger is present in the passenger seat and when the presence or absence of the passenger is unknown. The effect is significant because there is no concern that the device will operate, the cost of use can be reduced, and the operational reliability of the airbag device will not be impaired.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram showing the configuration of a vehicle airbag device to which the present invention is applied. FIG. 2 is a circuit diagram showing in detail the main parts of FIG. 1 ... Main sensor, 2 ... Safing sensor, 3 ...
… Power supply 4, 5 …… Ignition device, 6 …… Passenger detection circuit,
7, 8 ... Transistor, 10 ... Occupant sensor, 10a ...
… Switch, 11 …… Fail-safe circuit, 12 …… Warning device, 14,15 …… Comparator

Claims (1)

(57) [Scope of utility model registration request] 1. Control of an airbag for a passenger seat for inflating a bag-shaped airbag from the front toward an occupant in the passenger seat during sudden deceleration of the vehicle to protect the occupant from a front obstacle. A device, wherein an occupant sensor for detecting the presence or absence of a passenger in the passenger seat, and the airbag device can be operated only when a passenger is present in the passenger seat based on a signal from the occupant sensor. A control device for a passenger airbag, comprising: a control circuit; and a fail-safe circuit that always activates the airbag device when an abnormality of the occupant sensor is detected.